and working of the invention may be described simultaneously. (Ib.)

Thus we may describe a portion of a steam engine and the action of its parts as follows: "In fig. 4, A', A2, A3, A', are the pillars supporting B, the frame. On B are fixed C1 C2, the bed-plates, carrying D1 D2, the bearings on which E, the cylinder, oscillates. F is the piston-rod, connected with G, the crank, which has a projection, g, that unlocks at each revolution of the catch h, and thus sets free the rod i and lever k, at the same time moving the eccentric H, so as to work the valve motion l.” (Ib., 66.)

In other cases it is more conducive to a clear understanding of the invention to describe the parts separately first, and to begin another description afterwards, in which their mutual relation is set forth. Thus a brew

ing apparatus may be described: "In fig. 5, B' is one of the two vats and its accompanying parts. The other is similar. The vat holds from one hundred to one hundred and fifty gallons, and the height and diameter are nearly equal. The upper part is hooped by rings k1 k2 k3, made of fine-tempered iron, about four inches distant from each other. I is a ball-cock, regulating the supply of liquor from the pipe m, which is turned in a siphon form, and dips into the heating trough n, so as to be covered with four or five inches of water," &c. after thus describing all the parts we may begin again, thus: "The operation of the machine was as follows: The liquor flows from the pipe m through the trough n, by the ball-cock l, into the vat B'," &c.

And

The first portion of such an explanation of the drawings is something like a descriptive catalogue of the

parts represented and of the use of such in relation to those immediately adjoining it, while the second portion omits such minute description, on the supposition that it is understood, and proceeds to show the relation of all the parts in the operation of the machine.

When there are many figures, it affords relief to the mind to state at once, in the commencement, what each figure represents, thus: "Figure 1 represents an elevation of my improved loom; fig. 2 is a vertical section of the same, by a plane perpendicular to the axis of the breastbeam; fig. 3 represents the shed when open; and fig. 4 the same when closed; figs. 5, 6, 7, and 8 represent the machinery at each corner of the woof; and fig. 9 the apparatus for inserting the wire, (on a larger scale.") (1b., 67.)

124. DOTTED LINES.-Dotted lines are usually referred to when indicating parts represented as behind or covered by those nearer, as well as the paths of points when in motion. Great caution is required when it is endeavored to set forth particular parts of the machine as new parts, by distinguishing them in drawings. (Ib., 68.)

It is to be recollected that the object of the specification is not to describe the drawings, but with the drawings to describe the invention. (lb., 68.)

125. MODEL. In all cases which admit of representation by model, the applicant, if required by the Commissioner, shall furnish one of convenient size to exhibit advantageously the several parts of his invention or discovery. (Act of July 8, 1870, § 29.)

126. SPECIMENS OF INGREDIENTS.-When the invention or discovery is of a composition of matter, the applicant, if required by the Commissioner, shall furnish spec

imens of ingredients and of the composition sufficient in quantity for the purpose of experiment. (Ib., § 28.)

The Commissioner shall cause to be classified and arranged in suitable cases, in the rooms and galleries provided for that purpose, the models, specimens of composition, fabrics, manufactures, works of art, and designs which have been or shall be deposited in said office; and said rooms and galleries shall be kept open during suitable hours for public inspection. (Act of July 8, 1870, § 13.)

127. COMMISSIONER MAY DISPENSE WITH MODEL.-An applicant, upon filing his specification and drawings, may submit to the Commissioner the question whether he shall deposit a model or specimen of his invention; otherwise a model will be required in every case, except for designs, where the nature of the invention admits of such illustration. (Patent Office Rules, July, 1870.)

128. REQUISITES OF MODEL.-The model must clearly exhibit every feature of the machine which forms the subject of a claim of invention. (Ib.)

It must be neatly and substantially made, of durable material. It should be made as small as possible, but not in any case more than one foot in length, width, or height. If made of pine or other soft wood, it should be, painted, stained, or varnished. Glue must not be used, but the parts should be so connected as to resist the action of heat or moisture. (Ib.)

A working model is always desirable, in order to enable the office fully and readily to understand the precise operation of the machine. The name of the inventor, and of the assignee, (if assigned,) and also the title of the invention, must be affixed upon it in a permanent

manner. When the invention is a composition of matter, a specimen of each of the ingredients and of the composition must accompany the application, and the name of the inventor and of the assignee (if there be one) must be permanently affixed thereto. (Ib.)

129. MODEL WILL BE RETURNED IF THE APPLICATION IS REJECTED OR ABANDONED.-The model, unless otherwise disposed of, will be returned to the applicant upon demand and at the expense of the applicant, in all cases, when an application has been rejected more than two years; and, in any pending case of less than two years' standing, upon the filing of a formal abandonment of the application, signed by applicant. (Ib.)

Models filed as exhibits, in interference and other cases, may be returned to the applicant, at the discretion of the Commissioner. (Ib.)

The Commissioner may restore to the respective applicants such of the models belonging to rejected applications as he shall not think necessary to be preserved, or he may sell or otherwise dispose of them after the application has been finally rejected for one year, paying the proceeds into the treasury, as other patent moneys are directed to be paid. (Act of July 8, 1870, § 14.)

130. MODEL AS EVIDENCE.-Under the word patent, used in reference to the description of the thing patented, is included the patent, the specification attached to it, and the model and drawing, which are to be taken together, as making up the description. (Whitney v. Emmett, Bald., 314.)

And the model may be resorted to for clearer information respecting the invention described in the specification. (Hogg v. Emerson, 6 How., 485.)

Models of machines, about which there is a question, are a kind of evidence which is entitled to the highest credibility, and which, like figures, cannot lie. (Morris v. Barrett, 1 Fish., 461.)

Evidence superior to and unaffected by the interest or prejudice of partisans, or by the opinions (the reveries they may often be called) of experts. (McCormick v. Talcott, 20 How., 409.)

131. TO WHAT APPLICANT IS TO MAKE OATH.-The applicant shall make oath or affirmation that he does verily believe himself to be the original and first inventor or discoverer of the art, machine, manufacture, composition, or improvement for which he solicits a patent; that he does not know and does not believe that the same was ever before known or used; and shall state of what country he is a citizen. (Act of July 8, 1870, § 30.)

The applicant is not required to make oath or affirmation that he is the original and first inventor, but that he believes himself to be so. He cannot know absolutely whether he first invented or discovered the thing for